Test systems for testing electronic devices, such as semiconductor dies, are known. In some such test systems, electrically conductive probes are brought into contact with terminals of the electronic devices. Power and test signals are then provided to the electronic devices through the probes, and the responses of the electronic devices to the test signals are monitored through the probes. To establish reliable electrical connections between the probes and the terminals of the electronic devices, the probes typically must be generally aligned with the terminals. In some test scenarios, aligning the probes with the terminals includes adjusting an attitude (e.g., tilt, orientation, planarity, etc.) of the contact tips of the probes to correspond generally with an attitude of the terminals. Moreover, in some test scenarios, thermal gradients, mechanical loads placed on the probes, and other such causes can cause undesired movement of the probes. In some instances, these movements can cause the probes to become so misaligned with the terminals that electrical connections between some or all of the probes and some or all of the terminals of the electronic devices are lost during testing of the electronic devices. Embodiments of the present invention are directed to improvements in adjusting an attitude of a probe card assembly and providing mechanical stiffening of the probe card assembly.